Photogravure was invented in 1876. Similar to Intaglio printing, it is printing process in which an image is photographed through a screen on to a sensitized printing plate that after development is etched. Basically, the artist creates a film positive on a piece of film, so it is transparent. Light is then projected through the film positive onto some type of plate or surface, which has a tissue coated with a gel cover. Through a number of exposures and washings, parts of the gel hardens, while other do not. Recessed areas form with each trial that can then be filled with ink for printing. It is important to the history of photography because it is the earliest known form for reproducing photographs on film.
